Nucleic acids encoding tumor marker

ABSTRACT

The invention encompasses a novel tumor marker which is present on tumor cells and absent on corresponding normal cells, nucleic acid encoding the tumor marker, and a novel method of isolating DNA encoding the tumor marker or a gene which is differentially expressed in tissues.

GOVERNMENT RIGHTS

This invention was made part with U.S. Government support. Therefore, the U.S. Government has certain rights in the invention.

This application is a continuation of application Ser. No. 08/348,747, filed Dec. 1, 1994, which was a continuation of application Ser. No. 08/146,4888, Oct. 29, 1993 (both now abandoned).

FIELD OF THE INVENTION

The invention relates to proteins that serve as tumor markers for human carcinoma and to methods of isolating differentially expressed genes.

BACKGROUND OF THE INVENTION

Tumor markers for human tumor cells have been largely limited to activated oncogenes and their products, for example, the myc, ras, fos, and erbB2 genes and their encoded oncoproteins. In addition, activated anti-oncogenes, such as RB, p53, and DCC, have been identified in normal cells but do not appear to be present in tumor cells. Oncogene and anti-oncogene products have proven difficult to use as consistent predictors of tumor and normal tissue, respectively, due to the relatively low level of expression of the genes encoding these proteins. Thus, there is a need in the art for a tumor marker which is not only differentially expressed in tumor and normal tissue, but also consistently detectable in human tumor tissue and consistently absent in the corresponding normal tissue.

A common method used to identify genes differentially or uniquely expressed in tumors, in cells responding to growth factors, and in differentiated cell types such as, among others, T cells, adipocytes, neurons, and hepatocytes is the subtractive hybridization technique (S. W. Lee et al., Proc. Natl. Acad. Sci. USA 80:4699, 1983). A method of differential display of eukaryotic mRNA by means of the polymerase chain reaction (PCR) has recently been developed (P. Liang et al., Science 257:967, 1992). This method utilizes oligo dT linked to two additional bases as the primer for reverse transcription driven by reverse transcriptase. cDNA fragments are then amplified by Taq DNA polymerase-based PCR using an oligo dT primer along with one additional primer. The amplified cDNAs are then resolved by DNA sequencing gels. There is a need in the art for a streamlined and simplified process for isolating cDNAs corresponding to differentially expressed mRNAs.

SUMMARY OF THE INVENTION

The invention is based on the discovery of a novel protein, TC1 (SEQ ID NO: 4), which is a tumor marker, particularly for invasive and metastatic tumors, and the gene encoding this protein.

The invention thus encompasses the TC1 protein (SEQ ID NO: 4), which is useful as a tumor marker for tumor diagnosis and therapy, particularly for colorectal, breast, and gastrointestinal tumors, and for metastatic tumors emanating from these tumor types. TC1 is also a useful marker in general for tumor cell invasion and metastasis. mRNA encoding TC1 is not expressed in most cultured tumor cells, i.e., in vitro, but is expressed once these cells are grown in vivo. Because later stage and deeply invasive tumors contain higher levels of TC1 protein than other tumor tissues, TC1 appears to be a particularly useful marker for later stage cancers.

TC1 protein may also serve as a target in tumor targeted therapy to prevent tumor cell metastasis and thus invasion of additional organs. For example, a polypeptide fragment of the TC1 protein may be used as an antagonist of TC1 biological activity; e.g., where TC1 biological activity includes invasion and metastasis, the polypeptide fragment may be administered to a patient afflicted with the tumor in order to inhibit the spread of the tumor to other tissues. Alternatively, a truncated portion of TC1 which retains the invasive and metastatic biological activities of the full-length molecule will be useful for screening for antagonists of TC1 activity. Potentially useful polypeptides are described herein.

The invention also encompasses nucleotide probes based on the TC1 nucleotide sequence; e.g., 10, 20, 30, 40, etc. nucleotides in length. Such probes are useful for PCR-based tumor detection and in situ hybridization of tumor tissue sections. In addition, probes whose nucleotide sequences are based on homologies with other genes or proteins having sequences related to TC1, i.e., genes of the TC1 family, two of which are described herein, are useful for detecting additional genes belonging to the TC1 family of genes.

The invention thus also encompasses methods of screening for agents which inhibit expression of the TC1 gene (SEQ ID NO: 3) in vitro, comprising exposing a metastatic cell line in which TC1 mRNA is detectable in cultured cells to an agent suspected of inhibiting production of the TC1 mRNA; and determining the level of TC1 mRNA in the exposed cell line, wherein a decrease in the level of TC1 MRNA after exposure of the cell line to the agent is indicative of inhibition of TC1 mRNA production.

Alternatively, the screening method may include in vitro screening of a metastatic cell line in which TC1 protein is detectable in cultured cells to an agent suspected of inhibiting production of the TC1 protein; and determining the level of TC1 protein in the cell line, wherein a decrease in the level of TC1 protein after exposure of the cell line to the agent is indicative of inhibition of TC1 protein production.

The invention also encompasses in vivo methods of screening for agents which inhibit expression of the TC1 gene, comprising exposing a mammal having tumor cells in which TC1 mRNA or protein is detectable to an agent suspected of inhibiting production of TC1 mRNA or protein; and determining the level of TC1 mRNA or protein in tumor cells of the exposed mammal. A decrease in the level of TC1 mRNA or protein after exposure of the mammal to the agent is indicative of inhibition of TC1 gene expression.

These screening methods are particularly applicable to breast tumor cells, colon tumor cells, or tumor cells of the gastrointestinal tract.

The invention also encompasses a method of treating late stage cancer, comprising administering to a mammal afflicted with a late stage cancer a therapeutically effective amount of an inhibitor of TC1. Late stage cancers include those which have become deeply invasive in a tissue or which have metastisized to other tissues.

TC1 is detectable in patient blood, urine, sputum or other body fluid using a monoclonal antibody specific for a TC1 epitope. Thus, the invention also encompasses antibodies specific for TC1. Monoclonal antibodies specific for TC1 may be used for tumor imaging to localize tumor position and size. TC1-specific monoclonal antibodies are also useful as screening and diagnostic agents in immunohistochemical staining of tissue sections to distinguish tumor cells from normal cells. Thus, anti-TC1 antibodies are particularly useful where they recognize cells which produce the TC1 protein, when such cells are paraffin-embedded and/or formalin-fixed. One example of such an antibody is the monoclonal antibody anti-TC1-1 produced by the hybridoma deposited with the American Type Culture Collection as ATCC Deposit No. HB 11481.

In another aspect, the invention also features a novel method, called palindromic PCR, for identifying and isolating a gene, e.g., a gene which is differentially expressed in different types of tissues. The method is based on the use of short DNA primers and corresponding palindromic nucleotide sequences in the nucleotide sequence to be isolated.

Thus, the invention encompasses a method for producing a double stranded cDNA that includes the steps of contacting an mRNA with a DNA primer under stringent hybridization conditions to form a first hybrid molecule, the primer having a length of from 8 to 12 nucleotides and, preferably, 9 to 11 nucleotides; subjecting the first hybrid molecule to an enzyme having reverse transcriptase activity, to produce a first DNA strand complementary to at least a portion of the mRNA; contacting the first DNA strand with the primer under stringent hybridization conditions to form a second hybrid molecule; and subjecting the second hybrid molecule to an enzyme having DNA polymerase activity, to produce a second DNA strand complementary to the first DNA strand. Preferably, the method also includes the step of amplifying the first and second DNA strands.

In preferred embodiments, a single enzyme provides both the reverse transcriptase activity and the DNA polymerase activity. One example of a suitable such enzyme is rTth DNA polymerase from the thermophilic eubacterium Therzmus thermophilus.

As used herein, the term "palindromic nucleotide sequences" means that a double stranded DNA molecule contains a specific DNA sequence in both its coding strand and its anti-parallel strand, when those strands are read in the same direction, e.g., 5' to 3'.

The specific sequence of the DNA primer is arbitrary in that it is based upon individual judgment. In some instances, the sequence can be entirely random or partly random for one or more bases. Preferably, the GC content of the primer is between 40% and 60%, most preferably about 50%. In other instances, the arbitrary sequence can be selected to contain a specific ratio of each deoxynucleotide. The arbitrary sequence can also be selected to contain, or not to contain, a recognition site for a specific restriction endonuclease.

The DNA primer can contain a sequence that is known to be a "consensus sequence" of an mRNA of known sequence. As defined herein, a "consensus sequence" is a sequence that has been found in a gene family of proteins having a similar function or similar properties. The use of a primer that includes a consensus sequence may result in the cloning of additional members of a desired gene family.

Palindromic PCR enables genes that are altered in their frequency of expression, as well as those that are constitutively or differentially expressed, to be identified by simple visual inspection and isolated. The method also allows the cloning and sequencing of selected mRNAs, so that the investigator may determine the relative desirability of the gene product prior to screening a comprehensive cDNA library for the full length gene product.

Further objects and advantages of the invention will be apparent in light of the following description and the claims.

The file of this patent contains at least one color drawing. Copies of this patent with color drawing(s) will be provided by the Patent and Trademark Office upon request and payment of the necessary fee.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a polyacrylamide gel of size-separated cDNAs that were reverse transcribed from paired mRNAs from colon carcinoma (T) and adjacent normal colon tissue (N) and subsequently amplified.

FIG. 2A is a gel in which the TC1 cDNA fragment identified in FIG. 1 was recovered and re-amplified.

FIG. 2B is a Northern Blot of three pairs of RNA from colon carcinoma (T) and their adjacent normal colon tissue (N) probed with 32P-labeled TC1 cDNA.

FIG. 3 shows the nucleotide sequence (described herein as SEQ ID NO: 1) and corresponding amino acid sequence (SEQ ID NO: 2) of the 636 bp partial TC1 clone.

FIG. 4 shows the nucleotide sequence (SEQ ID NO: 3) and corresponding amino acid sequence (SEQ ID NO: 4) of the full-length TC1 gene and protein.

FIG. 5 is a sequence comparison of the four internal homologous domains of TC1 (SEQ ID NO: 4), each approximately 135 amino acids.

FIG. 6A is a schematic representation of the four repeats of TC1.

FIG. 6B is a proposed schematic arrangement of the four repeated domains and the N- and C-terminal domains.

FIG. 7 shows the amino acid sequence identity between TC1 (SEQ ID NO: 4) and Big-h3 (SEQ ID NO: 17).

FIG. 8 is a Northern Blot of five pairs of RNA from colon carcinoma (T) and adjacent normal colon tissue (N) probed with 32P-labeled Big-h3 cDNA, the bottom panel representing control RNA probed with 32P-labeled B-actin.

FIG. 9 shows amino acid sequence homology between TC1 (SEQ ID NO: 4) and Fasciclin I from Grasshopper (GrF) (SEQ ID NO: 18) and Drosophila (DrF) (SEQ ID NO: 19).

FIG. 10 is a Schematic representation showing that, on average, in every 202 bases of sequence in one strand of cDNA, there is one 9-base sequence exactly palindromic to that in a region of its antiparallel strand.

FIG. 11 shows the relationship between the palindromic frequency and the number of bases in a putative DNA primer, as determined by cDNA Matrix analysis.

FIG. 12 is a schematic representation of the method of the invention, palindromic PCR, driven by the enzyme rTth DNA polymerase with one DNA primer in one reaction tube; the dotted line indicates mRNA and the solid line indicates cDNA; the short jagged line represents the single DNA primer.

FIG. 13A shows the effect of the length of the DNA primer on the cDNA amplification patterns; the length and nucleotide sequence of each primer are: A, 8-mer (5'-TGTCGAGA); B', 9-mer (5'-TGTCCAGAC); C', 10-mer (5'-TGTCCAGATG) (SEQ ID NO: 5); D', 11-mer (5'-TGTCCAGATGC) (SEQ ID NO: 6); E', 12-mer (5'-TGTCCAGATGAC) (SEQ ID NO: 7).

FIG. 13B shows the effect of the GC content of the DNA primer on the cDNA amplification patterns; the GC content and nucleotide sequence of each primer (10-mer) are: A', 40% (5'-TGTCCAGATA) (SEQ ID NO: 8); B', 50% (5'-TGTCCAGATG) (SEQ ID NO: 5); C', 60% (5'-TGTCCAGACG) (SEQ ID NO: 9): D', 70% (5'-TGTCCAGCCG) (SEQ ID NO: 10); E', 80% (5'-TGTCCCGCCG) (SEQ ID NO: 11); F', 90% (5'-TGCCCGGCCG) (SEQ ID NO: 12).

FIG. 13C shows the effect of the sequence specificity of the DNA primer on the cDNA amplification patterns; 10-mer primers with the same GC content but different sequences are: A', 5'-TGATGCACTC (SEQ ID NO: 13); B', 5'-TGAGCTACTC (SEQ ID NO: 14); C', 5'-TGACTGACTC (SEQ ID NO: 15).

FIG. 13D shows palindromic PCR performed by rTth DNA polymerase (A) with reverse transcription cycles (RT cycles) and (B) without RT cycles.

FIG. 14A-14B show the identification of differentially expressed genes in human colon carcinoma.

FIG. 15 shows reamplification of the TC1 cDNA fragment isolated from colon carcinoma; the PCR product was analyzed on a 1.0% agarose gel; a 0.63 Kb cDNA fragment (arrow) was detected.

FIG. 16 is an autoradiogram of DNA sequencing gels showing the presence of PP1 primer sequence (5'-CTGATCCATG) (SEQ ID NO: 16) at the 5'-end of both strands of the TC1 cDNA fragment; cloning sites are indicated by arrows, sequences below arrows are pBS (KS) vector sequences reading from T3 primer and T7 primer.

FIG. 17 is a Northern Blot of 24 pairs of colon carcinoma (T) and their adjacent normal tissue (N) probed with 32P-labeled TC1 cDNA.

FIG. 18 shows the Tumor/Normal RNA Ratio from Northern Blot results of FIG. 17.

FIG. 19 is a Northern Blot of RNA from carcinoma cells which result from metastasis from colon carcinoma to liver (LM) and their adjacent normal liver (NL) probed with ³² P-labeled TC1 cDNA.

FIG. 20 shows a Northern Blot of RNA from breast cancer cell line MCF-7 (1) and colon cancer cell line CX-1 (2) cultured in vitro, and MCF-7 tumor (3) and CX-1 tumor (4) grown in vivo in nude mice.

FIGS. 21A-21D show staining of formalin-fixed and paraffin-embedded colon tumor tissue sections using the monoclonal antibody anti-TC1-1 and avidin-biotin-peroxidase detection.

FIG. 22 shows staining as described in FIG. 21, except that panels A, C, D represent breast invasive ductal carcinoma and panel B, normal breast tissue.

FIG. 23 shows staining as in FIG. 13, except that panels A and B represent gastric carcinoma, and panels C and D, deeply invasive colon carcinoma.

FIG. 24 is a Western Blot analysis of protein samples from two pairs of colon carcinoma and their adjacent normal colon (A) and two pairs of breast carcinoma and their adjacent normal breast (B), using a monoclonal antibody against TC1 protein as a probe.

FIG. 25A shows the ethidium bromide staining pattern of an RNA gel in which the same amount of RNA from JMN (1) and JMN1B (2) cells is loaded per lane.

FIG. 25B is a Northern Blot analysis of RNA from malignant mesothelioma cells JMN1B (2) and JMN (1) using TC1 cDNA as a probe.

FIG. 26 is a Western blot using a monoclonal antibody against TC1 to probe JMN1B cells grown in conditioned medium and whole cell lysate.

FIG. 27 shows JMN1B cells fixed with paraformaldehyde without subsequent permeabilization in panels A and B, and JMN1B cells fixed with paraformaldehyde and then permeabilized in panels C and D.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

TC1 (SEQ ID NO: 4) is a novel protein that is found in invasive and metastatic tumor cells. The nucleotide sequence encoding TC1 (SEQ ID NO: 3) was found using a novel technique described herein as palindromic PCR, a technique which enables identification and cloning of a gene that is differentially expressed in tissues. Cloning and sequencing of the gene encoding TC1 and characterization of the protein is described below, along with examples of how the protein is detected in invasive and metastatic cancers. Examples describing additional uses of the TC1 protein and its fragments, the nucleotide sequence encoding TC1 and fragments thereof, and antibodies specific for TC1 are also included.

Identification, Cloning and Detection of Expression of the TC1 Gene

The identification, cloning, and differential detection of expression of the TC1 gene (SEQ ID NO: 3) was performed as follows. A 636 bp cDNA fragment (SEQ ID NO: 1) containing TC1 sequences was identified and isolated by a rapid method termed palidromic PCR, described herein, from human surgical colon carcinoma tissue. Briefly, paired mRNAs were isolated from colon carcinoma tissue and adjacent normal colon tissue from the same patient, then matched mRNAs were reverse transcribed to cDNA and subsequently amplified by the palindromic PCR method described herein, which utilizes one DNA primer. Both reverse transcription and PCR reactions were driven by a single enzyme, rTth DNA polymerase, in a single tube. ³⁵ S or ³³ P-labeled PCR cDNA fragments were resolved on a DNA sequencing gel. As shown in FIG. 1, paired mRNAs from colon carcinoma (T) and adjacent normal colon tissue (N) were reverse transcribed to cDNA and subsequently amplified by palindromic PCR. ³⁵ S-labeled PCR cDNA fragments were then resolved on a DNA sequencing gel. A differential cDNA band (TC1) appeared to be present only in the tumor sample. This TC1 cDNA fragment was recovered from the sequencing gel and then reamplified with the same palindromic primer. This 636 bp fragment is identified with a horizontal arrow in FIG. 2A.

TC1 gene expression was examined in colon carcinoma cells and in the corresponding adjacent colon tissue, and the results were as follows. FIG. 2B is a Northern Blot of three pairs of RNA from colon carcinoma (T) and their adjacent normal colon tissue (N) probed with ³² P-labeled TC1 cDNA. TC1 mRNA was over-expressed in all three cases of colon carcinoma, whereas only very weak TC1 message appeared in the adjacent normal tissue. In the bottom panel of the blot, control RNA was blotted with ³² P-labeled cDNA encoding B-actin.

Northern Blot analysis of several pairs of Tumor/Normal total RNA using a 32P-labeled TC1 cDNA probe revealed that the TC1 mRNA size is about 3.6 Kb. This first TC1 cDNA fragment was cloned into a pBluescript plasmid DNA vector strategies. Nucleotide sequence analysis revealed that this fragment contained 636 bp with nucleotide sequences corresponding to the primer sequence at both 5'-ends of the double-stranded DNA (FIG. 3 and SEQ ID NO: 1). The corresponding predicted amino acid sequence is shown in FIG. 3 and provided in SEQ ID NO: 2. A search of the GenBank database with this cDNA fragment revealed that TC1 is a novel gene.

Nucleotide sequence analysis of the 636 bp TC1 cDNA fragment obtained by the described differential display method revealed that it contained a partial open reading frame. Therefore, this 636 bp cDNA fragment was used as probe to screen a cDNA library. Several overlapping clones were obtained and contained a 2997 bp sequence. To obtain the complete open reading frame for TC1, a modified 5'-end RACE technique was used to amplify the TC1 coding regions. The nucleotide and deduced amino acid sequence of full-length TC1 is shown in FIG. 4 and provided in SEQ ID NOS: 3 and 4. The N-terminal signal sequence is underlined; one predicted N-linked glycosylation site (NDT) is boxed and a polyadenylation signal (AATAAA) (SEQ ID NO: 3, nucleotide residues 3004-3009) is indicated. The cDNA contains 3126 bp with a potential polyadenylation sequences (AATAAA) at the 3'-end, beginning at residue 3004 (SEQ ID NO: 3, nucleotide residues 3004-3009). The open reading frame (ORF) encodes a 777-amino acid protein with a calculated molecular weight of 86 kD. The TC1 protein contains an amino-terminal signal peptide or secretory leader signal (ALPARILALALALAL) (SEQ ID NO: 4, amino acid residues 2-16), and one predicted site of N-linked 7 glycosylation at amino acid residue 605 (NDT). One Cemokine B family motif (C--C) was found at amino acid residue 85 (C--C) of TC1.

Analysis of the deduced amino acid sequence (SEQ ID NO: 4) revealed that TC1 contained four internal homologous domains of approximately 135 amino acids. A comparison of these repeats is shown in FIG. 5. Each boxed amino acid is identical with at least one other residue at that same position. The interdomain homologies range from 32% (between domains 2 and 4) to 18% (between domains 1 and 3). Some amino acid sequence such as TLFA/VPT/SNEAF (see SEQ ID NO: 4, amino acid residues 276-285), NGVIHXID (see SEQ ID NO: 4, amino acid residues 361-368) are highly conserved between all four repeats. The notations A/V and T/S are used herein to indicate that alanine or valine, and threonine or serine, respectively, may be found at these positions. In addition, the notation X is used herein to indicate that this position may include any amino acid. Each repeat starts with the most divergent sequence. The four repeats occur between residues 139-537 and are uninterrupted by non-homologous domains. A schematic representation of the four repeats of TC1 is shown in FIG. 6A. The four homologous repeats suggest a tetrameric structure (Mclachlan 1980; Zinn et al, 1988) with two binding sites, one at each intrachain dimer. The four repeats of TC1 may serve as ligand binding sites, with the N-terminal or C-terminal domains serving as the functional domain. One possible arrangement of the four repeated domains and the N- and C-terminal domains is shown schematically in FIG. 6B.

Palindromic PCR

Described below is a novel technique used to identify the TC1 mRNA and prepare TC1 cDNA. Although the sequence of bases in a coding and antisense strand of a cDNA molecule are, in a sense, "mirror images" of one another, we have found that with surprising frequency a short sequence of bases, e.g. 9 or 10, in one strand will be found to have an exact copy in its anti-parallel strand. We call these sequences "palindromic" sequences. This phenomenon has been used to develop a method of cDNA isolation and amplification.

In order to determine the frequency of occurrence or "palindromic frequency" of these anti-parallel repeats, a computer program called DNA Matrix (DNA Strider 1.2) was used to analyze double stranded cDNAs which were randomly selected from the GenBank database. DNA matrix analysis revealed the palindromic frequency of double strand cDNA to be surprisingly high and led to our development of a relationship between the number of bases in the chosen sequence, the "palindromic bases," and the palindromic frequency. Single strand cDNA (the mRNA strand) and its anti-parallel strand were compared, each from the 5' to 3' end by the DNA Matrix program. For example, as illustrated in FIG. 10, on the average, in every 202 bases of sequence in one strand of cDNA, there is one 9-base sequence that is exactly duplicated to that in another region of its antiparallel strand. The palindromic frequency found in native cDNA is much higher than that which would be calculated from random composition, suggesting that the nucleotide composition of double-stranded cDNA follows certain palindromic rules. As shown in FIG. 11, the palindromic frequency dramatically decreases when the number of bases in the searched segment increases. The key numbers of bases which lead to dramatic change of palindromic frequency are 9, 10 and 11 bases. This, then, is the theoretical basis for designing a primer for use in the DNA isolation and amplification method of the invention, palindromic PCR.

Table 1 presents the statistical data showing the palindromic frequency related to the number of bases in the searched segment.

                  TABLE 1     ______________________________________     Palindromic Frequency Related to No. of Bases in     Searched Segment as Revealed by cDNA Matrix Analysis     No. Bases in                Average Length to Find     Searched Segment                One X-Base Palindromic     (X Bases)  Sequence        Palindromic Frequency     ______________________________________      7 bases    18 bases       0.4      9 bases   202 bases       0.048     11 bases   872 bases       0.015     13 bases   >1996 bases     <0.007     ______________________________________

The principle of the method of palindromic PCR is shown in schematic representation in FIG. 12. The general strategy is to use a single primer and one enzyme combining both reverse transcriptase and DNA polymerase activities, e.g., rTth DNA polymerase (from the thermophilic eubacterium Thermus thermophilus), to perform both reverse transcription and polymerase chain reaction in one reaction tube. rTth DNA polymerase possesses a very efficient reverse transcriptase activity in the presence of MnCl₂ and a thermostable DNA polymerase activity in the presence of MgCl₂. The rTth DNA polymerase has been observed to be greater than 100-fold more efficient in coupled reverse transcription and PCR than the analogous DNA polymerase, Taq (T. W. Myers et al., Biochemistry 30:7661, 1991). In this reaction, an appropriate primer would allow anchored annealing to some regions of certain mRNA species that contain sequence complementary to the palindromic primer. This subpopulation of mRNAs is likely to be reverse transcribed by rTth DNA polymerase. A "Palindromic" primer apparently has a greater probability of anchoring to the coding regions of mRNA than oligo dT primer. Once mRNAs are reverse transcribed to form a first strand cDNA species, the same primer can anneal to some regions of the first strand cDNA and function as the "Downstream primer" in a PCR reaction. The same primer can also function as the "Upstream primer." When the primer anchors to first strand cDNAs, the annealing position to various cDNA molecules should, in principle, be at different distances in different molecules from the first annealing position. Therefore, the amplified cDNA fragments from various mRNAs will be of different sizes. Once these PCR-generated cDNA fragments are labeled with ³⁵ S-dATP or ³³ P-dATP, they can be resolved as a ladder by DNA sequencing gels. A display of cDNAs originating from various mRNAs can then be visualized after autoradiography.

The selection of the specific palindromic primer depends on three important factors: the length, the GC content, and the sequence specificity. DNA Matrix analysis has indicated that the ideal length of a primer for an appropriate palindromic frequency is from 9 to 11 bases. Therefore, a set of primers from 8 base to 12 base in length with 50% GC content was chosen for study. Our results showed that 9, 10, and 11 base primers gave an appropriate number of cDNA fragments readily resolvable by DNA sequencing gels (FIG. 13). To identify the GC content of the primer most suitable for this method, a set of 10-mer primers with GC content ranging from 40% to 90% was tested. The results suggested that a GC content from 40% to 80% is acceptable (FIG. 13). However, primers with 40% to 60% GC content appear to yield better results. To examine the effect of the specific sequence of the primer, 10-mer primers of different sequences each having 50% GC content was tested. As predicted, different primers gave rise to different cDNA patterns (FIG. 13). As little a difference as three bases led to totally different cDNA profiles.

cDNA patterns generated by palindromic PCR are highly stable. When the same conditions were used but the experiments repeated at different times, the patterns of the amplified cDNA fragments were highly reproduced, indicating the reliability of this method.

In order to be sure of detecting mRNAs with a low copy number, it was necessary to determine the sensitivity of this method. It has been reported that the amplification driven by rTth DNA polymerase is at least 100-fold greater than that by Taq polymerase. rTth DNA polymerase allows the detection of IL-1a mRNA, which has a very low copy number, in 8 pg of total cellular RNA (T. W. Myers et al., Biochemistry 30:7661, 1991). Thus, the higher efficiency of rTth DNA polymerase ensures that the palindromic PCR method of the invention provides high sensitivity. In addition, because rTth polymerase is thermostable, it can also be used to perform several RT cycles (reverse transcription cycles), which means several copies of first strand cDNA can be obtained from a single copy of mRNA. The sensitivity of the method is increased by performing multiple RT cycles using rTth polymerase (FIG. 13).

The method of the invention was tested in a search for differences in mRNA expression between human colon carcinoma and the adjacent normal epithelium from a surgical specimen. Paired mRNA preparations were reverse transcribed with a palindromic primer 5'-CTGATCCATG (designated as PP-1 primer (SEQ ID NO: 16)) in the presence of MnCl₂ followed by PCR with the same primer in the presence of MgCl₂ using rTth DNA polymerase. The reaction products were then analyzed by DNA sequencing gels. About 70-110 amplified cDNA fragments ranging from 100-700 bases from both preparations were detected (FIG. 14). Whereas overall cDNA patterns between tumor and normal tissue are similar, significant differences were detected by this method. Most cDNA bands showed the same intensity between tumor and normal preparations, but two cDNA bands designated as TC1 and TC2 appeared with increased intensities in tumor tissue (FIG. 14). A sample reaction protocol is described below.

To 1.1 μl of double distilled (dd) H₂ O is added 0.5 μl of 10×rTth DNA polymerase reverse transcriptase (RT) buffer (100 mM Tris-Hcl, pH 8.3, 900 mM KCl) , 0.5 μl of 10 mM MnCl₂, 0.4 μl of 2.50 mM dNTP, 1.0 μl (0. 50 μg) of one palindromic primer (9-11 mer), and 1.0 μl (100 ng) of mRNA to form Mix A in a total vol. of 4.5 μl. Mix A is heated in a 0.5 ml PCR tube at 65° C. for 6 min and then at 37° C. for 8 min. Next, 0.5 μl (1.25 unit) of rTth DNA polymerase is added, the reaction mixture is mixed well, spun briefly, incubated at 70° C. for 12 min and then placed on ice. Mix B which consisting of 12.5 μl of dd H₂ O, 2.0 μl of 10× chelating buffer (50% glycerol (v/v), 100 mM Tris-HCl, pH 8.3, 1M KCl, 0.5% Tween 20), 2.0 μl of 25 mM MgCl₂ solution, 2.50 nMdNTP and 2.0 μl of ³⁵ S-dATP (or ³³ P-dATP) is dispensed in the amount of 20 μl into each 5.0 μl RT reaction mixture. The samples are mixed and spun briefly and then overlaid with 25 μl of mineral oil. The polymerase chain reaction is then started: 94° C. for 40 sec., 40° C. for 2 min., 72° C. for 35 sec. (for 40 cycles, hold at 72° C. for 4 min.), and then 4° C.

For cDNA analysis, 7 μl of a PCR sample is mixed with 4 μl of sequencing loading buffer, samples are incubated at 80° C. for 3 min., and then placed on ice. 4.5 μl of the sample is loaded on a 6%-8% agarose DNA sequencing gel.

A gel slice containing a desirable cDNA band (such as TC1 ) was soaked in 200 μl of ddH₂ O for 20 min and then separated from 3M paper with a clean forcep or a plastic pipette tip. The gel was removed and pounded with an autoclaved plastic pipette tip. Elution buffer (20 μl) was added and the mixture was vortexed and left at room temperature for 4 hrs or overnight. After centrifugation, cDNA fragments in 10 μl eluent were reamplified by rTth DNA polymerase with the same palindromic primer, as described. After one 40-cycle PCR, the reamplified cDNA could be detected by agrose gels stained with ethidium bromide. The amount of cDNA generated was sufficient for cloning and preparing a probe for Northern Blot analysis. FIG. 15 shows the gel obtained when the TC1 cDNA band was subjected to elution and reamplification. Total PCR product of the TC1 fragment was 2.5 μg.

The reamplified TC1 cDNA fragment was treated with T4 DNA polymerase and cloned into pBluescript plasmid DNA vector at SmaI site by blunt end ligation. The nucleotide sequence of the TC1 fragment (SEQ ID NO: 1) showed that a sequence identical to the PP1 primer (SEQ ID NO: 16) is indeed present at the 5'-end of both strands of the TC1 fragment (FIG. 16). This result confirms that the 5'-ends of both complementary chains of the TC1 cDNA fragment used the same palindromic primer during palindromic PCR as discussed above. It also implies that the same palindromic primer sequence is present at the 5'-ends of both strands for every PCR product in the same reaction. These results establish that a single 9-11 base palindromic primer can effectively prime reverse transcription and then serve as both a "Downstream primer" and an "Upstream primer" in palindromic PCR amplification.

The method of the invention differs from other methods in a number of ways. In palindromic PCR, only a single primer (9-11 bases) is used and is sufficient to prime reverse transcription as well as to support subsequent PCR for a display of nearly 100 cDNA species. Because the pattern of amplified cDNAs depends on the sequence of the single palindromic primer, the species of mRNAs that are subjected to amplification can readily be controlled by a proper sequence of the palindromic primer. If a group or family of genes shares certain sequences, a primer can be chosen from such a sequence, and a specific display of this set of mRNAs can readily be performed. Likewise, computer analysis of the Genebank database may reveal additional sequences useful as a primer shared by a set of related genes. The use of such a primer by the method of the invention would allow the display for the expression of a given set of genes. Palindromic PCR provides an easy, sensitive and economical way to identify and isolate differentially expressed genes related to tumor and other disease.

Differential expression of TC1 DNA in normal tissue and tumor cells

Northern Blot analysis, as described above, confirmed the differential expression of TC1 mRNA in colon carcinoma tissue, and the absence of TC1 mRNA in the corresponding normal tissue. Evaluation of the expression of TC1 mRNA in additional cases of colon carcinoma at different stages was also undertaken. Surgical specimens of 24 cases of human primary colon carcinoma and 6 cases of liver metastases were examined by Northern hybridization of total RNA with ³² P-labeled TC1 probe.

A Northern Blot of 24 pairs of colon carcinoma (T) and their adjacent normal tissue (N) probed with ³² P-labeled TC1 cDNA is shown in FIG. 17. It is evident from the results that the level of TC1 mRNA in tumor tissue is much greater than the level in adjacent normal tissue in all 24 cases. The TC1 mRNA levels vary in different cases of carcinoma. Panels I and II show A: TC1 mRNA and B: Control; Panel III shows TC1 mRNA and control (Actin) mRNA.

FIG. 18 shows the Tumor/Normal RNA Ratio from Northern Blot results of FIG. 17. The horizontal line indicates the mean Tumor/Normal ratio. TC1 mRNA was abundantly expressed in all 24 cases of primary colon carcinoma and 6 cases of liver metastases, whereas only a small amount of TC1 mRNA was detected in a few cases of paired adjacent normal tissue. The mRNA level of TC1 was much greater in primary colon carcinoma than in paired adjacent normal colonic epithelium in all 24 cases. The Tumor/Normal ratio varied from 5.6 to 92, and the mean Tumor/Normal ratio being 32. The Tumor/Normal ratio, when plotted against the Duke's stage of disease, gave evidence for increasing TC1 expression with increasing stage of colon carcinoma.

In all six cases of paired colon carcinoma metastatic to liver, the TC1 mRNA level was much higher in metastatic tumor than in adjacent normal liver tissue. FIG. 19 shows a Northern Blot of RNA from metastatic colon carcinoma to liver (LM) and their adjacent normal liver (NL) probed with ³² P-labeled TC1 cDNA. TC1 mRNA was expressed only in metastatic tumor in 5 of 6 samples. Only one sample of normal liver tissue expressed a very weak TC1 message. The Tumor/Normal ratio is greater than 64. These results suggested that differential expression of TC1 may be associated with human colorectal cancer progression and biological aggressiveness of the disease.

In vivo and in vitro expression of TC1 mRNA

The expression of TC1 mRNA in cultured cancer cells and in vivo tumor cells was analyzed and is described below. TC1 was overexpressed in tumor tissue in vivo. The expression of TC1 mRNA in cultured cancer cell lines in vitro was examined by Northern Blot analysis. RNAs isolated from twelve colon cancer cell lines (HT29, Clone A, MIP101, CX-1, Morser, CCL227, CCL228, etc.) derived from different stage of human colon carcinoma, two melanoma cell lines (LOX, A2058), one breast cancer cell line (MCF-7), two cervical cancer cell lines (Hela, A431), three bladder cancer cell lines (EJ, T24, MB49), one pancreas cancer cell line (CRL1420), two hepatoma cell lines (HepG2, HepG3) and four normal cell lines (FS-2, MRC-5, 498A, CV-1) were screened by Northern Blot analysis. However, the TC1 transcript could not be detected in all of these cell lines. This result suggested that TC1 expression was dramatically decreased or indeed turned off in cultured cancer cells. However, after cultured cancer cells were injected into nude mice to grow tumor in vivo, TC1 mRNA expression turned on again and its mRNA level could be detected by Northern Blot analysis.

FIG. 20 shows a Northern Blot of RNA from breast cancer cell line MCF-7 (1) and colon cancer cell line CX-1 (2) cultured in vitro, and MCF-7 tumor (3) and CX-1 tumor (4) grown in vivo in nude mice. TC1 mRNA in colon cancer cell line CX-1 and breast cancer cell line MCF-7 cultured in vitro could not be detected by Northern Blot analysis. After cultured CX-1 and HT29 cells were injected into nude mice to form tumors in vivo, TC1 mRNA was detectable by Northern Blot analysis, the TC1 mRNA levels being dramatically increased in vivo. This result suggests that TC1 gene expression was turned on or dramatically increased in the tumor cells in vivo. Thus, the differential expression of the TC1 gene appears to be related to invasion and metastasis of tumor cells in vivo. The regulation of TC1 gene expression in vivo and in vitro could be a very important model to understand tumorigenesis and tumor malignant behavior.

Expression of TC1 protein

The expression of TC1 protein in in vivo tumor cells, cultured carcinoma cells, and in corresponding normal cells was examined, and is described below. The TC1 gene (SEQ ID NO:3) was cloned into a plasmid expression vector, and recombinant TC1 protein (SEQ ID NO:4) was expressed in bacteria. Several monoclonal antibodies against the bacterially-produced TC1 protein were raised, as will be described below. A variety of formalin-fixed and paraffin-embedded tumor tissue sections were examined by immunohistochemical staining with a mouse monoclonal anti-TC1 antibody anti-TC1-1 using an avidin-biotinylated-peroxidase detection technique. Strong positive staining of TC1 was found in primary colon carcinoma (FIG. 21, panel A), colon carcinoma metastatic to liver (FIG. 21, panel C) and lymph node (FIG. 21, panel D), breast carcinoma (FIG. 22, panels A, C, D) and gastric carcinoma (FIG. 23, panels A,B). The TC1 protein level in tumor tissue is much greater than the level of TC1 in adjacent normal tissue (FIGS. 21B, 23B).

These results, which represent the staining of sixteen cases of different stages of primary colon carcinoma, eight cases of colon tumor metastatic to liver and lymph node, fourteen cases of breast carcinoma and five cases of gastric carcinoma, suggested the following three conclusions. First, the TC1 protein level appeared to be different in different types of carcinoma, with protein levels being highest in breast carcinoma. Second, the advance edge of the deeper invasive tumor appeared stain stronger for TC1, suggesting a greater prevalence of TC1 protein at the advance edge of the tissue. Third, the move advanced stages of tumor appeared to contain more TC1 protein.

FIG. 24 is a Western Blot analysis of protein samples from two pairs of colon carcinoma and their adjacent normal colon (A) and two pairs of breast carcinoma and their adjacent normal breast (B), using a monoclonal antibody against TC1 protein as a probe. A major 86 kd protein (arrow) was detected by anti-TC1 antibody in tumor samples (T) but not in normal samples (N). The Western Blot analysis confirmed that tumor tissue contained significantly more TC1 protein than the corresponding adjacent normal tissue.

TC1 gene expression

The presence of TC1 mRNA and protein in malignant mesothelioma cells was examined, and is described below. More than 42 cell lines have been screened for TC1 gene expression by Northern Blot analysis. However, only two cell lines, JMN1B and JMN, express detectable mRNA by Northern Blot analysis. JMN1B and JMN are malignant mesothelioma, JMN1B being a subline of JMN cells with showing enhanced tumorigenicity after passage of JMN cells through a nude mouse. FIG. 25 is a Northern Blot analysis of RNA from malignant mesothelioma cells JMNlB and JMN using TC1 cDNA as a probe. The results presented in Panel 25B demonstrate that TC1 mRNA level in JMN1B cells (2) is much greater than that in JMN cells (1). Panel 25A shows the ethidum bromide staining pattern of an RNA gel in which the same amount of JMN (1) and JMN1B (2) RNA is loaded per lane.

The Northern Blot analysis revealed that the TC1 mRNA level is much higher in JMN1B than in JMN, the JMN1B/JMN ratio being approximately 14. Higher expression of TC1 mRNA in JMN1B could be related to the observed greater tumorigenicity of JMN1B cells. It has been found that JMN1B cells can secrete an "EGF-like" growth factor called transformed mesothelial growth factor (TMGF) that satisfies the EGF requirement of normal human mesothelial cells. The difference in the levels of TC1 mRNA in JMN1B and JMN cells provides an ideal cell model to understand the regulation of TC1 expression and its relation to tumorigenicity.

Sequence analysis of the deduced amino acid sequence has revealed that the TC1 protein (SEQ ID NO: 4) contained a secretory leader signal at its N-terminus. The secretion of TC1 protein was confirmed by Wester Blot analysis of conditioned medium of JMN1B cells. JMN1B cells were cultured in regular medium until 90% confluent, then cultured in serum free medium for two days. This serum free conditioned medium was analyzed by immunoblotting with anti-TC1 monoclonal antibody. FIG. 26 is a Western blot analysis using a monoclonal antibody against TC1 to probe JMN1B cells grown in conditioned medium and whole cell lysate. Two major bands (about 86 kd and 104 kd) were recognized by anti-TC1 antibody both in JMN1B cell conditioned medium (1) and whole cell lysate (2). Numbers on the left indicate the position of molecular weight standards in kilodalton. The protein size of the lower molecular weight 86 kd band is consistent with that of deduced TC1 protein, whereas the higher molecular weight 104 kd band is consistent with a TC1 glycoprotein. There is one predicted site of N-linked glycosylation at the amino acid residue 605(NDT) of deduced TC1 protein sequence. There are 60 threonine residues and 36 serine residues in the deduced TC1 sequence, each of which is a potential site of O-linked glycosylation.

Human malignant mesothelioma cell line JMN1B can express abundant TC1. This cell line was used to study the distribution and localization of TC1 protein by immunoflorescent staining with an anti-TC1 monoclonal antibody followed by Rhodamine conjugated goat anti-mouse IgG secondary antibody. When JMN1B cells were fixed with paraformaldehyde without subsequent permeabilization, the positive staining was seen on the cell surface or outside of the cell (FIG. 27, panels A, B), which confirms the secretion of TC1 protein. When JMN1B cells were fixed with paraformaldehyde and then permeabilized, positive staining appeared in the Golgi complex and the endoplasmic reticulum (ER) in the cell (FIG. 27, panels C,D), suggesting that TC1 protein is synthesized in the ER and Golgi complex. The staining in the Golgi complex is clearly evident, indicating that glycosylation of TC1 protein may be located in the Golgi complex. The TC1 protein distribution pattern also suggests that TC1 is a secreted glycoprotein.

Without being bound to one theory as to the biological function of TC1, observations as to the prevalence and expression of TC1 mRNA and protein indicate that TC1 may be related to tumor malignant behavior such as invasion and metastases. These observations include the following: TC1 is significantly overexpressed in tumor tissue; TC1 is a secreted protein; later stage tumor expresses higher levels of TC1; deeper invasive tumor contains higher levels of TC1 protein; TC1 expression turns off in cultured tumor cells in vitro and turns on again after cells grow tumor tissue in vivo. These observations indicate that the function of TC1 is not related to tumor cell proliferation, but is more likely involved in tumor malignant behavior in vivo, such as invasion and metastases.

TC1 is a member of a Family of Proteins

A FASTA search of the GenBank and EMBL database with the TC1 open reading frame indicated that the protein is unique. However, TC1 whole protein shared 45% sequence identity with a TGF-beta inducible gene, Big-h3, at the amino acid level, suggesting that TC1 and Big-h3 may belong to a new gene family. The identity between TC1 (SEQ ID NO: 4) and Big-h3 (SEQ ID NO: 17) at the amino acid level is shown in FIG. 7. In FIG. 7, identical amino acids between TC1 and Big-h3 are boxed. Several stretches of amino acids GSFTXFAPSNEAW (see SEQ ID NO: 4, amino acid residues 136-148 ), TLXAPTNEAFEKXP (see SEQ ID NO: 4, amino acid residues 276-287), ATNGVVHXIDXV (see SEQ ID NO: 4, amino acid residues 224-235), LYXGQXLETXGGKXLRVFVYR (see SEQ ID NO: 4, amino acid residues 449-469), HYPNGXVTVNCAR (see SEQ ID NO: 4, amino acid residues 204-216) are highly conserved between TC1 and Big-h3 (compare SEQ ID NO: 4 with SEQ ID NO:17). Northern Blot analysis showed that the TC1 gene is expressed from a larger transcript than Big-h3, and DNA sequence analysis indicated that TC1 contains a longer open reading frame encoding a higher molecular weight protein than the Big-h3 gene. It has been found that Big-h3 also contains four internal repeats. The amino acid sequence homology and structural similarity between TC1 and Big-h3 indicate their functional similarity and relationship. We found that Big-h3 mRNA is also much more abundant in colon carcinoma tissue than in adjacent normal colon tissue (FIG. 7). FIG. 8 is a Northern Blot of five pairs of RNA from colon carcinoma (T) and adjacent normal colon tissue (N) probed with ³² P-labeled Big-h3 cDNA. The blot shows Big-h3 mRNA level in colon carcinoma to be much higher than that in adjacent normal tissue. The bottom panel represents control RNA probed with ³² P-labeled B-actin.

In contrast to the expression pattern of TC1 mRNA, which is shown to be largely restricted to in vivo tumor tissue, Big-h3 mRNA is not only expressed in the tumor tissue, but also expressed in the cultured tumor cell lines and some normal cell lines. Though TC1 and Big-h3 shared significant homology, their responses to growth factors are distinctly different.

Fasciclin I, II, III are extrinsic membrane glycoproteins involved in the growth cone guidance during nervous system development in the insect embryo. A search of NBRF protein database revealed a significant homologous domain between TC1 and Fasciclin I from Grasshopper and Drosophila. One TC1 domain of 204 amino acids (amino acid residue 503-706) shared 30% identity with Grasshopper Fasciclin I, and shared 25% identity with Drosophila Fasciclin. FIG. 9 shows amino acid sequence homology between TC1 (SEQ ID NO: 4) and Fasciclin I from Grasshopper (GrF) (SEQ ID NO: 18) and Drosophila (DrF) (SEQ ID NO: 19). Boxed amino acids are identical with at least one other amino acid at that same position.

It has been found that Fasciclin also contained four internal homologous domains, each consisting of approximately 150 amino acids. The domains of TC1 and Fasciclin I share some highly conserved amino acid stretches such as TXFV/APTNXAF (see SEQ ID NO: 4), amino acid residues 538-547), and VXHVVDXXLXP compare SEQ ID NO: 4 SEQ ID NOS: 18 and 19) (see SEQ ID NO: 4, amino acid residues 626-636).

The most conserved sequence among TC1, Big-h3 and Fasciclin is TXFA/VPTNXAF/W (see SEQ ID NO: 4, amino acid residues 538-547). All four internal repeats in TC1 or Big-h3 or Fasciclin I also share the most conserved sequence TXFA/VPT/SNXAF/W (see SEQ ID NO: 4, amino acid residues 538-547). This sequence appears to be an important motif of this gene family.

Screening for antagonists to TC1 function

The invention also includes methods of screening for agents which inhibit TC1 gene expression, whether such inhibition be at the transcriptional or translational level.

Screening methods, according to the invention, for agents which inhibit expression of the TC1 gene in vitro will include exposing a metastatic cell line in which TC1 mRNA is detectable in culture to an agent suspected of inhibiting production of the TC1 mRNA; and determining the level of TC1 mRNA in the exposed cell line, wherein a decrease in the level of TC1 mRNA after exposure of the cell line to the agent is indicative of inhibition of TC1 mRNA production.

Alternatively, such screening methods may include in vitro screening of a metastatic cell line in which TC1 protein is detectable in culture to an agent suspected of inhibiting production of the TC1 protein; and determining the level of TC1 protein in the cell line, wherein a decrease in the level of TC1 protein after exposure of the cell line to the agent is indicative of inhibition of TC1 protein production.

The invention also encompasses in vivo methods of screening for agents which inhibit expression of the TC1 gene, comprising exposing a mammal having tumor cells in which TC1 mRNA or protein is detectable to an agent suspected of inhibiting production of TC1 mRNA or protein; and determining the level of TC1 mRNA or protein in tumor cells of the exposed mammal. A decrease in the level of TC1 mRNA or protein after exposure of the mammal to the agent is indicative of inhibition of TC1 gene expression.

According to the invention, agents can be screened in vitro or in vivo as follows. For in vitro screening, a metastatic cell line, e.g., JMN1B, may be cultured in vitro and exposed to an agent suspected of inhibiting TC1 expression in an amount and for a sufficient to inhibit such expression. For in vivo screening, a mammal afflicted with a late stage cancer, particularly one of breast cancer, colon cancer, or cancer of the gastrointestinal tract, is exposed to the agent at a dosage and for a time sufficient to inhibit expression of TC1. A late stage cancer is defined by the Duke's stage of the cancer; i.e., late stage cancers correspond to Duke's stages 3-4. The amount or dosage of the agent which is effective to inhibit TC1 expression may be determined using serial dilutions of the agent. The level of TC1 mRNA or protein may be determined using an aliquot of cells from the cell culture or the in vivo tumor and performing Northern Blot analysis or Western Blot analysis, respectively. The agent will be considered inhibitory if the level of TC1 mRNA or protein decreases by more than 50%, and preferably more than 70-80%, relative to the same cell line which has not been exposed to the agent. Examples of potential inhibitors of TC1 mRNA or protein production include but are not limited to antisense RNA, competitive inhibitors of the TC1 protein such as fragments of the TC1 protein itself, or antibodies to TC1 protein. Candidate TC1 inhibitory fragments include, but are not limited to, TL/YFA/VPT/SNE/DAF/W (see SEQ ID NO: 4, amino residues 276-285) and NGV/AI/VHXI/VD/F (see SEQ ID NO: 4, amino acid residues 361-368).

Use of antagonists to TC1 functions

The invention also encompasses the treatment of late stage cancers by administration to a mammal afflicted with a late stage cancer one or more of the above-selected inhibitory agents. Late stage cancers, particularly those of the breast, colon, or gastrointestinal tract, are treated according to the invention by administering the inhibitory agent to a mammal afflicted with a late stage cancer in an amount and for a time sufficient to decrease the level of TC1 protein or mRNA.

The mode of administration may be intra-venously, intra-peritoneally, by intra-muscular or intra-dermal injection, or orally. Administration may be by single dose, or may be continuous or intermittent. The dosage of inhibitory agent is that dosage which is effective to inhibit TC1 production, i.e., within the range of 10 μg/kg body weight-100 gm/kg body weight, preferably, within the range of 1 mg/kg body weight-1 gm/kg body weight, most preferably 10-100 mg/kg body weight.

Production of monoclonal antibodies reactive with TC1

An anti-TC1 antibody is produced according to Kohler and Milstein, Nature, 256:495-497 (1975), Eur. J. Immunol. 6:511-519 (1976), both of which are hereby incorporated by reference, using the TC1 protein or a fragment thereof as the immunizing antigen. Hybridomas produced by the above process are selected for anti-TC1 antibodies using the TC1 as an antigen in an ELISA assay. The single type of immunoglobulin produced by a such a hybridoma is specific for a single antigenic determinant, or epitope, on the TC1 antigen. Certain TC1-specific antibodies, for example, anti-TC1-1 produced by the hybridoma deposited with the American Type Culture Collection (ATCC) under the ATCC number HB 11481, are unique in that they recognize the TC1 protein, more specifically an epitope of the TC1 protein, in formaldehyde-fixed and paraffin-embedded tumor cells which bear TC1. Often TC1 antigenic portion is destroyed by this tissue treatment process such that the antibody will no longer recognize its cognate epitope.

Deposits

The following samples were deposited on Oct. 29, 1993, with the American Type Culture Collection (ATCC), 12301 Parklawn Drive, Rockville, Md. 20852.

    ______________________________________     Deposit         ATCC Accession No.     ______________________________________     TC1 gene in pBluescript                     HB 11481     plasmid DNA vector     Hybridoma TC-1  75599     ______________________________________

Applicants assignee, Dana-Farber Cancer Institute, Inc., represents that the ATCC is a depository affording permanence of the deposit and ready accessibility thereto by the public if a patent is granted. All restrictions on the availability to the public of the material so deposited will be irrevocably removed upon the granting of a patent. The material will be available during the pendency of the patent application to one determined by the Commissioner to be entitled thereto under 37 CFR 1,14 and 35 USC 122. The deposited material will be maintained with all the care necessary to keep it viable and uncontaminated for a period of at least five years after the most recent request for the furnishing of a sample of the deposited microorganism, and in any case, for a period of at least thirty (30) years after the date of deposit or for the enforceable life of the patent, whichever period is longer. Applicants' assignee acknowledges its duty to replace the deposit should the depository be unable to furnish a sample when requested due to the condition of the deposit.

OTHER EMBODIMENTS

The invention is not limited to those embodiments described herein, but may encompass modifications and variations which do not depart from the spirit of the invention. While the invention has been described in connection with specific embodiments thereof, it will be understood that further modifications are within the scope of the following claims.

    __________________________________________________________________________     SEQUENCE LISTING     (1) GENERAL INFORMATION:     (iii) NUMBER OF SEQUENCES: 19     (2) INFORMATION FOR SEQ ID NO:1:     (i) SEQUENCE CHARACTERISTICS:     (A) LENGTH: 636 base pairs     (B) TYPE: nucleic acid     (C) STRANDEDNESS: single     (D) TOPOLOGY: linear     (ii) MOLECULE TYPE: cDNA     (iii) HYPOTHETICAL: NO     (iv) ANTI-SENSE: NO     (ix) FEATURE:     (A) NAME/KEY: CDS     (B) LOCATION: 1..636     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:1:     CTGATCCATGGGAACCAGATTGCAACAAATGGTGTTGTCCATGTCATT48     LeuIleHisGlyAsnGlnIleAlaThrAsnGlyValValHisValIle     151015     GACCGTGTGCTTACACAAATTGGTACCTCAATTCAAGACTTCATTGAA96     AspArgValLeuThrGlnIleGlyThrSerIleGlnAspPheIleGlu     202530     GCAGAAGATGACCTTTCATCTTTTAGAGCAGCTGCCATCACATCGGAC144     AlaGluAspAspLeuSerSerPheArgAlaAlaAlaIleThrSerAsp     354045     ATATTGGAGGCCCTTGGAAGAGACGGTCACTTCACACTCTTTGCTCCC192     IleLeuGluAlaLeuGlyArgAspGlyHisPheThrLeuPheAlaPro     505560     ACCAATGAGGCTTTTGAGAAACTTCCACGAGGTGTCCTAGAAAGGATC240     ThrAsnGluAlaPheGluLysLeuProArgGlyValLeuGluArgIle     65707580     ATGGGAGACAAAGTGGCTTCCGAAGCTCTTATGAAGTACCACATCTTA288     MetGlyAspLysValAlaSerGluAlaLeuMetLysTyrHisIleLeu     859095     AATACTCTCCAGTGTTCTGAGTCTATTATGGGAGGAGCAGTCTTTGAG336     AsnThrLeuGlnCysSerGluSerIleMetGlyGlyAlaValPheGlu     100105110     ACGCTGGAAGGAAATACAATTGAGATAGGATGTGACGGTGACAGTATA384     ThrLeuGluGlyAsnThrIleGluIleGlyCysAspGlyAspSerIle     115120125     ACAGTAAATGGAATCAAAATGGTGAACAAAAAGGATATTGTGACAAAT432     ThrValAsnGlyIleLysMetValAsnLysLysAspIleValThrAsn     130135140     AATGGTGTGATCCATTTGATTGATCAGGTCCTAATTCCTGATTCTGCC480     AsnGlyValIleHisLeuIleAspGlnValLeuIleProAspSerAla     145150155160     AAACAAGTTATTGAGCTGGCTGGAAAACAGCAAACCACCTTCACGGAT528     LysGlnValIleGluLeuAlaGlyLysGlnGlnThrThrPheThrAsp     165170175     CTTGTGGCCCAATTAGGCTTGGCATCTGCTCTGAGGCCAGATGGAGAA576     LeuValAlaGlnLeuGlyLeuAlaSerAlaLeuArgProAspGlyGlu     180185190     TACACTTTGCTGGCACCTGTGAATAATGCATTTTCTGATGATACTCTC624     TyrThrLeuLeuAlaProValAsnAsnAlaPheSerAspAspThrLeu     195200205     AGCATGGATCAG636     SerMetAspGln     210     (2) INFORMATION FOR SEQ ID NO:2:     (i) SEQUENCE CHARACTERISTICS:     (A) LENGTH: 212 amino acids     (B) TYPE: amino acid     (D) TOPOLOGY: linear     (ii) MOLECULE TYPE: protein     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:2:     LeuIleHisGlyAsnGlnIleAlaThrAsnGlyValValHisValIle     151015     AspArgValLeuThrGlnIleGlyThrSerIleGlnAspPheIleGlu     202530     AlaGluAspAspLeuSerSerPheArgAlaAlaAlaIleThrSerAsp     354045     IleLeuGluAlaLeuGlyArgAspGlyHisPheThrLeuPheAlaPro     505560     ThrAsnGluAlaPheGluLysLeuProArgGlyValLeuGluArgIle     65707580     MetGlyAspLysValAlaSerGluAlaLeuMetLysTyrHisIleLeu     859095     AsnThrLeuGlnCysSerGluSerIleMetGlyGlyAlaValPheGlu     100105110     ThrLeuGluGlyAsnThrIleGluIleGlyCysAspGlyAspSerIle     115120125     ThrValAsnGlyIleLysMetValAsnLysLysAspIleValThrAsn     130135140     AsnGlyValIleHisLeuIleAspGlnValLeuIleProAspSerAla     145150155160     LysGlnValIleGluLeuAlaGlyLysGlnGlnThrThrPheThrAsp     165170175     LeuValAlaGlnLeuGlyLeuAlaSerAlaLeuArgProAspGlyGlu     180185190     TyrThrLeuLeuAlaProValAsnAsnAlaPheSerAspAspThrLeu     195200205     SerMetAspGln     210     (2) INFORMATION FOR SEQ ID NO:3:     (i) SEQUENCE CHARACTERISTICS:     (A) LENGTH: 3126 base pairs     (B) TYPE: nucleic acid     (C) STRANDEDNESS: single     (D) TOPOLOGY: linear     (ii) MOLECULE TYPE: cDNA     (iii) HYPOTHETICAL: NO     (iv) ANTI-SENSE: NO     (ix) FEATURE:     (A) NAME/KEY: CDS     (B) LOCATION: 43..2376     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:3:     GCCACCATGTAGCCCGCGTCACCGTTCTGCGCATTCCGCAGCATGGCTCTGCCT54     MetAlaLeuPro     GCCCGAATCCTCGCTCTGGCCCTCGCACTGGCGCTCGGACCCGCCGTG102     AlaArgIleLeuAlaLeuAlaLeuAlaLeuAlaLeuGlyProAlaVal     5101520     ACACTGGCCAACCCGGCGAGAACGCCGTACGAGCTGGTACTCCAGAAG150     ThrLeuAlaAsnProAlaArgThrProTyrGluLeuValLeuGlnLys     253035     AGCTCGGCACGAGGGGGTCGGGACCAAGGCCCAAATGTCTGTGCCCTT198     SerSerAlaArgGlyGlyArgAspGlnGlyProAsnValCysAlaLeu     404550     CAACAGATTTTGGGCACCAAAAAGAAATACTTCAGCACTTGTAAGAAC246     GlnGlnIleLeuGlyThrLysLysLysTyrPheSerThrCysLysAsn     556065     TGGTATAAAAAGTCCATCTGTGGACAGAAAACGACTGTGTTATATGAA294     TrpTyrLysLysSerIleCysGlyGlnLysThrThrValLeuTyrGlu     707580     TGTTGCCCTGGTTATATGAGAATGGAAGGAATGAAAGGCTGCCCAGCA342     CysCysProGlyTyrMetArgMetGluGlyMetLysGlyCysProAla     859095100     GTTTTGCCCATTGACCATGTTTATGGCACTCTGGGCATCGTGGGAGCC390     ValLeuProIleAspHisValTyrGlyThrLeuGlyIleValGlyAla     105110115     ACCACAACGCAGCGCTATTCTGACGCCTCAAAACTGAGGGAGGAGATC438     ThrThrThrGlnArgTyrSerAspAlaSerLysLeuArgGluGluIle     120125130     GAGGGAAAGGGATCCTTCACTTACTTTGCACCGAGTAATGAGGCTTGG486     GluGlyLysGlySerPheThrTyrPheAlaProSerAsnGluAlaTrp     135140145     GACAACTTGGATTCTGATATCCGTAGAGGTTTGGAGAGCAACGTGAAT534     AspAsnLeuAspSerAspIleArgArgGlyLeuGluSerAsnValAsn     150155160     GTTGAATTACTGAATGCTTTACATAGTCACATGATTAATAAGAGAATG582     ValGluLeuLeuAsnAlaLeuHisSerHisMetIleAsnLysArgMet     165170175180     TTGACCAAGGACTTAAAAAATGGCATGATTATTCCTTCAATGTATAAC630     LeuThrLysAspLeuLysAsnGlyMetIleIleProSerMetTyrAsn     185190195     AATTTGGGGCTTTTCATTAACCATTATCCTAATGGGGTTGTCACTGTT678     AsnLeuGlyLeuPheIleAsnHisTyrProAsnGlyValValThrVal     200205210     AATTGTGCTCGAATCATCCATGGGAACCAGATTGCAACAAATGGTGTT726     AsnCysAlaArgIleIleHisGlyAsnGlnIleAlaThrAsnGlyVal     215220225     GTCCATGTCATTGACCGTGTGCTTACACAAATTGGTACCTCAATTCAA774     ValHisValIleAspArgValLeuThrGlnIleGlyThrSerIleGln     230235240     GACTTCATTGAAGCAGAAGATGACCTTTCATCTTTTAGAGCAGCTGCC822     AspPheIleGluAlaGluAspAspLeuSerSerPheArgAlaAlaAla     245250255260     ATCACATCGGACATATTGGAGGCCCTTGGAAGAGACGGTCACTTCACA870     IleThrSerAspIleLeuGluAlaLeuGlyArgAspGlyHisPheThr     265270275     CTCTTTGCTCCCACCAATGAGGCTTTTGAGAAACTTCCACGAGGTGTC918     LeuPheAlaProThrAsnGluAlaPheGluLysLeuProArgGlyVal     280285290     CTAGAAAGGATCATGGGAGACAAAGTGGCTTCCGAAGCTCTTATGAAG966     LeuGluArgIleMetGlyAspLysValAlaSerGluAlaLeuMetLys     295300305     TACCACATCTTAAATACTCTCCAGTGTTCTGAGTCTATTATGGGAGGA1014     TyrHisIleLeuAsnThrLeuGlnCysSerGluSerIleMetGlyGly     310315320     GCAGTCTTTGAGACGCTGGAAGGAAATACAATTGAGATAGGATGTGAC1062     AlaValPheGluThrLeuGluGlyAsnThrIleGluIleGlyCysAsp     325330335340     GGTGACAGTATAACAGTAAATGGAATCAAAATGGTGAACAAAAAGGAT1110     GlyAspSerIleThrValAsnGlyIleLysMetValAsnLysLysAsp     345350355     ATTGTGACAAATAATGGTGTGATCCATTTGATTGATCAGGTCCTAATT1158     IleValThrAsnAsnGlyValIleHisLeuIleAspGlnValLeuIle     360365370     CCTGATTCTGCCAAACAAGTTATTGAGCTGGCTGGAAAACAGCAAACC1206     ProAspSerAlaLysGlnValIleGluLeuAlaGlyLysGlnGlnThr     375380385     ACCTTCACGGATCTTGTGGCCCAATTAGGCTTGGCATCTGCTCTGAGG1254     ThrPheThrAspLeuValAlaGlnLeuGlyLeuAlaSerAlaLeuArg     390395400     CCAGATGGAGAATACACTTTGCTGGCACCTGTGAATAATGCATTTTCT1302     ProAspGlyGluTyrThrLeuLeuAlaProValAsnAsnAlaPheSer     405410415420     GATGATACTCTCAGCATGGATCAGCGCCTCCTTAAATTAATTCTGCAG1350     AspAspThrLeuSerMetAspGlnArgLeuLeuLysLeuIleLeuGln     425430435     AATCACATATTGAAAGTAAAAGTTGGCCTTAATGAGCTTTACAACGGG1398     AsnHisIleLeuLysValLysValGlyLeuAsnGluLeuTyrAsnGly     440445450     CAAATACTGGAAACCATCGGAGGCAAACAGCTCAGAGTCTTCGTATAT1446     GlnIleLeuGluThrIleGlyGlyLysGlnLeuArgValPheValTyr     455460465     CGTACAGCTGTCTGCATTGAAAATTCATGCATGGAGAAAGGGAGTAAG1494     ArgThrAlaValCysIleGluAsnSerCysMetGluLysGlySerLys     470475480     CAAGGGAGAAACGGTGCGATTCACATATTCCGCGAGATCATCAAGCCA1542     GlnGlyArgAsnGlyAlaIleHisIlePheArgGluIleIleLysPro     485490495500     GCAGAGAAATCCCTCCATGAAAAGTTAAAACAAGATAAGCGCTTTACG1590     AlaGluLysSerLeuHisGluLysLeuLysGlnAspLysArgPheThr     505510515     ACCTTCCTCAGCCTACTTGAAGCTGCAGACTTGAAAGAGCTCCTGACA1638     ThrPheLeuSerLeuLeuGluAlaAlaAspLeuLysGluLeuLeuThr     520525530     CAACCTGGAGACTGGACATTATTTGTGCCAACCAATGATGCTTTTAAG1686     GlnProGlyAspTrpThrLeuPheValProThrAsnAspAlaPheLys     535540545     GGAATGACTAGTGAAGAAAAAGAAATTCTGATACGGGACAAAAATGCT1734     GlyMetThrSerGluGluLysGluIleLeuIleArgAspLysAsnAla     550555560     CTTCAAAACATCATTCTTTATCACCTGACACCAGGAGTTTTCATTGGA1782     LeuGlnAsnIleIleLeuTyrHisLeuThrProGlyValPheIleGly     565570575580     AAAGGATTTGAACCTGGTGTTACTAACATTTTAAAGACCACACAAGGA1830     LysGlyPheGluProGlyValThrAsnIleLeuLysThrThrGlnGly     585590595     AGCAAAATCTTTCTGAAAGAAGTAAATGATACACTTCTGGTGAATGAA1878     SerLysIlePheLeuLysGluValAsnAspThrLeuLeuValAsnGlu     600605610     TTGAAATCAAAAGAATCTGACATCATGACAACAAATGGTGTAATTCAT1926     LeuLysSerLysGluSerAspIleMetThrThrAsnGlyValIleHis     615620625     GTTGTAGATAAACTCCTCTATCCAGCAGACACACCTGTTGGAAATGAT1974     ValValAspLysLeuLeuTyrProAlaAspThrProValGlyAsnAsp     630635640     CAACTGCTGGAAATACTTAATAAATTAATCAAATACATCCAAATTAAG2022     GlnLeuLeuGluIleLeuAsnLysLeuIleLysTyrIleGlnIleLys     645650655660     TTTGTTCGTGGTAGCACCTTCAAAGAAATCCCCGTGACTGTCTATAGA2070     PheValArgGlySerThrPheLysGluIleProValThrValTyrArg     665670675     CCCACACTAACAAAAGTCAAAATTGAAGGTGAACCTGAATTCAGACTG2118     ProThrLeuThrLysValLysIleGluGlyGluProGluPheArgLeu     680685690     ATTAAAGAAGGTGAAACAATAACTGAAGTGATCCATGGAGAGCCAATT2166     IleLysGluGlyGluThrIleThrGluValIleHisGlyGluProIle     695700705     ATTAAAAAATACACCAAAATCATTGATGGAGTGCCTGTGGAAATAACT2214     IleLysLysTyrThrLysIleIleAspGlyValProValGluIleThr     710715720     GAAAAAGAGACACGAGAAGAACGAATCATTACAGGTCCTGAAATAAAA2262     GluLysGluThrArgGluGluArgIleIleThrGlyProGluIleLys     725730735740     TACACTAGGATTTCTACTGGAGGTGGAGAAACAGAAGAAACTCTGAAG2310     TyrThrArgIleSerThrGlyGlyGlyGluThrGluGluThrLeuLys     745750755     AAATTGTTACAAGAAGACACACCCGTGAGGAAGTTGCAAGCCAACAAA2358     LysLeuLeuGlnGluAspThrProValArgLysLeuGlnAlaAsnLys     760765770     AAAAGTTCAAGGATCTAGAAGACGATTAAGGGAAGGTCGTTCTCAGTGAAAATCC2413     LysSerSerArgIle     775     AAAAACCAGAAAAAAATGTTTATACAACCCTAAGTCAATAACCTGACCTTAGAAAATTGT2473     GAGAGCCAAGTTGACTTCAGGAACTGAAACATCAGCACAAAGAAGCAATCATCAAATAAT2533     TCTGAACACAAATTTAATATTTTTTTTTCTGAATGAGAAACATGAGGGAAATTGTGGAGT2593     TAGCCTCCTGTGGTAAAGGAATTGAAGAAAATATAACACCTTACACCCTTTTTCATCTTG2653     ACATTAAAAGTTCTGGCTAACTTTGGAATCCATTAGAGAAAAATCCTTGTCACCAGATTC2713     ATTACAATTCAAATCGAAGAGTTGTGAACTGTTATCCCATTGAAAAGACCGAGCCTTGTA2773     TGTATGTTATGGATACATAAAATGCACGCAAGCCATTATCTCTCCATGGGAAGCTAAGTT2833     ATAAAAATAGGTGCTTGGTGTACAAAACTTTTTATGATCAAAAGGCTTTGCACATTTCTA2893     TATGAGTGGGTTTACTGGTAAATTATGTTATTTTTTACAACTAATTTTGTACTCTCAGAA2953     TGTTTGTCATATGCTTCTTGCAATGCATATTTTTTAATCTCAAACGTTTCAATAAAACCA3013     TTTTTCAGATATAAAGAGAATTACTTCAAATTGAGTAATTCAGAAAAACTCAAGATTTAA3073     GTTAAAAAGTGGTTTGGACTTGGGAATAGGACTTTATACCTCTTTCTCGTGCC3126     (2) INFORMATION FOR SEQ ID NO:4:     (i) SEQUENCE CHARACTERISTICS:     (A) LENGTH: 777 amino acids     (B) TYPE: amino acid     (D) TOPOLOGY: linear     (ii) MOLECULE TYPE: protein     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:4:     MetAlaLeuProAlaArgIleLeuAlaLeuAlaLeuAlaLeuAlaLeu     151015     GlyProAlaValThrLeuAlaAsnProAlaArgThrProTyrGluLeu     202530     ValLeuGlnLysSerSerAlaArgGlyGlyArgAspGlnGlyProAsn     354045     ValCysAlaLeuGlnGlnIleLeuGlyThrLysLysLysTyrPheSer     505560     ThrCysLysAsnTrpTyrLysLysSerIleCysGlyGlnLysThrThr     65707580     ValLeuTyrGluCysCysProGlyTyrMetArgMetGluGlyMetLys     859095     GlyCysProAlaValLeuProIleAspHisValTyrGlyThrLeuGly     100105110     IleValGlyAlaThrThrThrGlnArgTyrSerAspAlaSerLysLeu     115120125     ArgGluGluIleGluGlyLysGlySerPheThrTyrPheAlaProSer     130135140     AsnGluAlaTrpAspAsnLeuAspSerAspIleArgArgGlyLeuGlu     145150155160     SerAsnValAsnValGluLeuLeuAsnAlaLeuHisSerHisMetIle     165170175     AsnLysArgMetLeuThrLysAspLeuLysAsnGlyMetIleIlePro     180185190     SerMetTyrAsnAsnLeuGlyLeuPheIleAsnHisTyrProAsnGly     195200205     ValValThrValAsnCysAlaArgIleIleHisGlyAsnGlnIleAla     210215220     ThrAsnGlyValValHisValIleAspArgValLeuThrGlnIleGly     225230235240     ThrSerIleGlnAspPheIleGluAlaGluAspAspLeuSerSerPhe     245250255     ArgAlaAlaAlaIleThrSerAspIleLeuGluAlaLeuGlyArgAsp     260265270     GlyHisPheThrLeuPheAlaProThrAsnGluAlaPheGluLysLeu     275280285     ProArgGlyValLeuGluArgIleMetGlyAspLysValAlaSerGlu     290295300     AlaLeuMetLysTyrHisIleLeuAsnThrLeuGlnCysSerGluSer     305310315320     IleMetGlyGlyAlaValPheGluThrLeuGluGlyAsnThrIleGlu     325330335     IleGlyCysAspGlyAspSerIleThrValAsnGlyIleLysMetVal     340345350     AsnLysLysAspIleValThrAsnAsnGlyValIleHisLeuIleAsp     355360365     GlnValLeuIleProAspSerAlaLysGlnValIleGluLeuAlaGly     370375380     LysGlnGlnThrThrPheThrAspLeuValAlaGlnLeuGlyLeuAla     385390395400     SerAlaLeuArgProAspGlyGluTyrThrLeuLeuAlaProValAsn     405410415     AsnAlaPheSerAspAspThrLeuSerMetAspGlnArgLeuLeuLys     420425430     LeuIleLeuGlnAsnHisIleLeuLysValLysValGlyLeuAsnGlu     435440445     LeuTyrAsnGlyGlnIleLeuGluThrIleGlyGlyLysGlnLeuArg     450455460     ValPheValTyrArgThrAlaValCysIleGluAsnSerCysMetGlu     465470475480     LysGlySerLysGlnGlyArgAsnGlyAlaIleHisIlePheArgGlu     485490495     IleIleLysProAlaGluLysSerLeuHisGluLysLeuLysGlnAsp     500505510     LysArgPheThrThrPheLeuSerLeuLeuGluAlaAlaAspLeuLys     515520525     GluLeuLeuThrGlnProGlyAspTrpThrLeuPheValProThrAsn     530535540     AspAlaPheLysGlyMetThrSerGluGluLysGluIleLeuIleArg     545550555560     AspLysAsnAlaLeuGlnAsnIleIleLeuTyrHisLeuThrProGly     565570575     ValPheIleGlyLysGlyPheGluProGlyValThrAsnIleLeuLys     580585590     ThrThrGlnGlySerLysIlePheLeuLysGluValAsnAspThrLeu     595600605     LeuValAsnGluLeuLysSerLysGluSerAspIleMetThrThrAsn     610615620     GlyValIleHisValValAspLysLeuLeuTyrProAlaAspThrPro     625630635640     ValGlyAsnAspGlnLeuLeuGluIleLeuAsnLysLeuIleLysTyr     645650655     IleGlnIleLysPheValArgGlySerThrPheLysGluIleProVal     660665670     ThrValTyrArgProThrLeuThrLysValLysIleGluGlyGluPro     675680685     GluPheArgLeuIleLysGluGlyGluThrIleThrGluValIleHis     690695700     GlyGluProIleIleLysLysTyrThrLysIleIleAspGlyValPro     705710715720     ValGluIleThrGluLysGluThrArgGluGluArgIleIleThrGly     725730735     ProGluIleLysTyrThrArgIleSerThrGlyGlyGlyGluThrGlu     740745750     GluThrLeuLysLysLeuLeuGlnGluAspThrProValArgLysLeu     755760765     GlnAlaAsnLysLysSerSerArgIle     770775     (2) INFORMATION FOR SEQ ID NO:5:     (i) SEQUENCE CHARACTERISTICS:     (A) LENGTH: 10 base pairs     (B) TYPE: nucleic acid     (C) STRANDEDNESS: single     (D) TOPOLOGY: linear     (ii) MOLECULE TYPE: cDNA     (iii) HYPOTHETICAL: NO     (iv) ANTI-SENSE: NO     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:5:     TGTCCAGATG10     (2) INFORMATION FOR SEQ ID NO:6:     (i) SEQUENCE CHARACTERISTICS:     (A) LENGTH: 11 base pairs     (B) TYPE: nucleic acid     (C) STRANDEDNESS: single     (D) TOPOLOGY: linear     (ii) MOLECULE TYPE: cDNA     (iii) HYPOTHETICAL: NO     (iv) ANTI-SENSE: NO     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:6:     TGTCCAGATGC11     (2) INFORMATION FOR SEQ ID NO:7:     (i) SEQUENCE CHARACTERISTICS:     (A) LENGTH: 12 base pairs     (B) TYPE: nucleic acid     (C) STRANDEDNESS: single     (D) TOPOLOGY: linear     (ii) MOLECULE TYPE: cDNA     (iii) HYPOTHETICAL: NO     (iv) ANTI-SENSE: NO     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:7:     TGTCCAGATGAC12     (2) INFORMATION FOR SEQ ID NO:8:     (i) SEQUENCE CHARACTERISTICS:     (A) LENGTH: 10 base pairs     (B) TYPE: nucleic acid     (C) STRANDEDNESS: single     (D) TOPOLOGY: linear     (ii) MOLECULE TYPE: cDNA     (iii) HYPOTHETICAL: NO     (iv) ANTI-SENSE: NO     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:8:     TGTCCAGATA10     (2) INFORMATION FOR SEQ ID NO:9:     (i) SEQUENCE CHARACTERISTICS:     (A) LENGTH: 10 base pairs     (B) TYPE: nucleic acid     (C) STRANDEDNESS: single     (D) TOPOLOGY: linear     (ii) MOLECULE TYPE: cDNA     (iii) HYPOTHETICAL: NO     (iv) ANTI-SENSE: NO     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:9:     TGTCCAGACG10     (2) INFORMATION FOR SEQ ID NO:10:     (i) SEQUENCE CHARACTERISTICS:     (A) LENGTH: 10 base pairs     (B) TYPE: nucleic acid     (C) STRANDEDNESS: single     (D) TOPOLOGY: linear     (ii) MOLECULE TYPE: cDNA     (iii) HYPOTHETICAL: NO     (iv) ANTI-SENSE: NO     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:10:     TGTCCAGCCG10     (2) INFORMATION FOR SEQ ID NO:11:     (i) SEQUENCE CHARACTERISTICS:     (A) LENGTH: 10 base pairs     (B) TYPE: nucleic acid     (C) STRANDEDNESS: single     (D) TOPOLOGY: linear     (ii) MOLECULE TYPE: cDNA     (iii) HYPOTHETICAL: NO     (iv) ANTI-SENSE: NO     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:11:     TGTCCCGCCG10     (2) INFORMATION FOR SEQ ID NO:12:     (i) SEQUENCE CHARACTERISTICS:     (A) LENGTH: 10 base pairs     (B) TYPE: nucleic acid     (C) STRANDEDNESS: single     (D) TOPOLOGY: linear     (ii) MOLECULE TYPE: cDNA     (iii) HYPOTHETICAL: NO     (iv) ANTI-SENSE: NO     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:12:     TGCCCGGCCG10     (2) INFORMATION FOR SEQ ID NO:13:     (i) SEQUENCE CHARACTERISTICS:     (A) LENGTH: 10 base pairs     (B) TYPE: nucleic acid     (C) STRANDEDNESS: single     (D) TOPOLOGY: linear     (ii) MOLECULE TYPE: cDNA     (iii) HYPOTHETICAL: NO     (iv) ANTI-SENSE: NO     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:13:     TGATGCACTC10     (2) INFORMATION FOR SEQ ID NO:14:     (i) SEQUENCE CHARACTERISTICS:     (A) LENGTH: 10 base pairs     (B) TYPE: nucleic acid     (C) STRANDEDNESS: single     (D) TOPOLOGY: linear     (ii) MOLECULE TYPE: cDNA     (iii) HYPOTHETICAL: NO     (iv) ANTI-SENSE: NO     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:14:     TGAGCTACTC10     (2) INFORMATION FOR SEQ ID NO:15:     (i) SEQUENCE CHARACTERISTICS:     (A) LENGTH: 10 base pairs     (B) TYPE: nucleic acid     (C) STRANDEDNESS: single     (D) TOPOLOGY: linear     (ii) MOLECULE TYPE: cDNA     (iii) HYPOTHETICAL: NO     (iv) ANTI-SENSE: NO     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:15:     TGACTGACTC10     (2) INFORMATION FOR SEQ ID NO:16:     (i) SEQUENCE CHARACTERISTICS:     (A) LENGTH: 10 base pairs     (B) TYPE: nucleic acid     (C) STRANDEDNESS: single     (D) TOPOLOGY: linear     (ii) MOLECULE TYPE: cDNA     (iii) HYPOTHETICAL: NO     (iv) ANTI-SENSE: NO     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:16:     CTGATCCATG10     (2) INFORMATION FOR SEQ ID NO:17:     (i) SEQUENCE CHARACTERISTICS:     (A) LENGTH: 683 amino acids     (B) TYPE: amino acid     (C) STRANDEDNESS: single     (D) TOPOLOGY: linear     (ii) MOLECULE TYPE: protein     (iii) HYPOTHETICAL: NO     (iv) ANTI-SENSE: NO     (v) FRAGMENT TYPE: internal     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:17:     MetAlaLeuPheValArgLeuLeuAlaLeuAlaLeuAlaLeuAlaLeu     151015     GlyProAlaAlaThrLeuAlaGlyProAlaLysSerProTyrGlnLeu     202530     ProLeuGlnHisSerArgLeuArgGlyArgGlnHisGlyProAsnVal     354045     CysAlaValThrLysValIleGlyThrAsnArgLysTyrPheThrAsn     505560     CysLysGlnTrpTyrGlnArgLysIleCysGlyLysSerThrValIle     65707580     SerTyrGluCysCysProGlyTyrGluLysValProGlyGluLysGly     859095     CysProAlaAlaLeuProLeuSerAsnLeuTyrGluThrLeuGlyVal     100105110     ValGlySerThrThrThrGlnLeuTyrThrAspArgThrGluLysLeu     115120125     ArgProGluMetGluGlyProGlySerPheThrIlePheAlaProSer     130135140145     AsnGluAlaTrpAlaSerLeuProAlaGluValLeuValSerLeuVal     150155160     SerAsnValAsnIleGluLeuLeuAsnAlaLeuArgTyrHisMetVal     165170175     GlyArgArgValLeuThrAspGluLeuLysHisGlyMetThrLeuThr     180185190     SerMetTyrGlnAsnSerAsnIleGlnIleHisHisTyrProAsnGly     195200205     IleValThrValAsnCysAlaArgLeuLeuLysAlaAspHisHisAla     210215220225     ThrAsnGlyValValHisLeuIleAspLysValIleSerThrIleThr     230235240     AsnAsnIleGlnGlnIleIleGluIleGluAspThrPheGluThrLeu     245250255     ArgAlaAlaValAlaAlaSerGlyLeuAsnThrMetLeuGluGlyAsn     260265270     GlyGlnTyrThrLeuLeuAlaProThrAsnGluAlaPheGluLysIle     275280285     ProSerGluThrLeuAsnArgIleLeuGlyAspProGluAlaLeuArg     290295300305     AspLeuLeuAsnAsnHisIleLeuLysSerAlaMetCysAlaGluAla     310315320     IleValAlaGlyLeuSerValGluThrLeuGluGlyThrThrLeuGlu     325330335     ValGlyCysSerGlyAspMetLeuThrIleAsnGlyLysAlaIleIle     340345350     SerAsnLysAspIleLeuAlaThrAsnGlyValIleHisTyrIleAsp     355360365     GluLeuLeuIleProAspSerAlaLysThrLeuPheGluLeuAlaAla     370375380385     GluSerAspValSerThrAlaIleAspLeuPheArgGlnAlaGlyLeu     390395400     GlyAsnHisLeuSerGlySerGluArgLeuThrLeuLeuAlaProLeu     405410415     AsnSerValPheLysAspGlyThrProProIleAspAlaHisThrArg     420425430     AsnLeuLeuArgAsnHisIleIleLysAspGlnLeuAlaSerLysTyr     435440445     LeuTyrHisGlyGlnThrLeuGluThrLeuGlyGlyLysLysLeuArg     450455460465     ValPheValTyrArgAsnSerLeuCysIleGluAsnSerCysIleAla     470475480     AlaHisAspLysArgGlyArgTyrGlyThrLeuPheThrMetAspArg     485490495     ValLeuThrProProMetGlyThrValMetAspValLeuLysGlyAsp     500505510     AsnArgPheSerMetLeuValAlaAlaIleGlnSerAlaGlyLeuThr     515520525     GluThrLeuAsnArgGluGlyValTyrThrValPheAlaProThrAsn     530535540545     GluAlaPheArgAlaLeuProProArgGluSerArgArgLeuLeuGly     550555560     AspAlaLysGluLeuAlaAsnIleLeuLysTyrHisIleGlyAspGlu     565570575     IleLeuValSerGlyGlyIleGlyAlaLeuValArgLeuLysSerLeu     580585590     GlnGlyAspLysLeuGluValSerLeuLysAsnAsnValValSerVal     595600605     AsnLysGluProValAlaGluProAspIleMetAlaThrAsnGlyVal     610615620625     ValHisValIleThrAsnValLeuGlnProProAlaAsnArgProGln     630635640     GluArgGlyAspGluLeuAlaAspSerAlaLeuGluIlePheLysGln     645650655     AlaSerAlaPheSerArgAlaSerGlnArgSerValArgLeuAlaVal     660665670     ProTyrGlnLysLeuLeuGluArgMetLysHis     675680     (2) INFORMATION FOR SEQ ID NO:18:     (i) SEQUENCE CHARACTERISTICS:     (A) LENGTH: 206 amino acids     (B) TYPE: amino acid     (C) STRANDEDNESS: single     (D) TOPOLOGY: linear     (ii) MOLECULE TYPE: protein     (iii) HYPOTHETICAL: NO     (iv) ANTI-SENSE: NO     (v) FRAGMENT TYPE: internal     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:18:     GlyGluLysSerLeuGluTyrLysIleArgAspAspProAspLeuSer     151015     GlnPheTyrSerTrpLeuGluHisAsnGluValAlaAsnSerThrLeu     202530     GlnLeuArgGlnValThrValPheAlaProThrAsnLeuAlaGlnPhe     354045     AsnTyrLysAlaArgAspGlyAspGluAsnIleIleLeuTyrHisMet     505560     ThrAsnLeuAlaHisSerLeuAspGlnLeuGlyHisLysValAsnSer     65707580     GluLeuAspGlyAsnProProLeuTrpIleThrArgArgArgAspThr     859095     IlePheValAsnAsnAlaArgValLeuThrGluArgSerAsnTyrGlu     100105110     AlaValAsnArgHisGlyLysLysGlnValLeuHisValValAspSer     115120125     ValLeuGluProValTrpSerThrSerGlyGlnLeuTyrAsnProAsp     130135140     AlaPheGlnPheLeuAsnGlnSerGluAsnLeuAspLeuGlyLeuHis     145150155160     ArgValArgSerPheArgGlnArgValPheGlnAsnGlnLysGlnAsn     165170175     AspPheLysLeuGluGlyLysHisThrPhePheIleProValAspGlu     180185190     GlyPheLysProLeuProArgProGluLysIleAspGlnLys     195200205     (2) INFORMATION FOR SEQ ID NO:19:     (i) SEQUENCE CHARACTERISTICS:     (A) LENGTH: 200 amino acids     (B) TYPE: amino acid     (C) STRANDEDNESS: single     (D) TOPOLOGY: linear     (ii) MOLECULE TYPE: protein     (iii) HYPOTHETICAL: NO     (iv) ANTI-SENSE: NO     (v) FRAGMENT TYPE: internal     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:19:     AlaAlaAlaAspLeuAlaAspLysLeuArgAspAspSerGluLeuSer     151015     GlnPheTyrSerLeuLeuGluSerAsnGlnIleAlaAsnSerThrLeu     202530     SerLeuArgSerCysThrIlePheValProThrAsnGluAlaPheGln     354045     ArgTyrLysSerLysThrAlaHisValLeuTyrHisIleThrThrGlu     505560     AlaTyrThrGlnLysArgLeuProAsnThrValSerSerAspMetAla     65707580     GlyAsnProProLeuTyrIleThrLysAsnSerAsnGlyAspIlePhe     859095     ValGlyAsnAlaArgIleIleProSerLeuSerValGluThrAsnSer     100105110     AspGlyLysArgGlnIleMetHisIleIleAspGluValLeuGluPro     115120125     LeuThrValLysAlaGlyHisSerAspThrProAsnAsnProAsnAla     130135140     LeuLysPheLeuLysAsnAlaGluGluPheAsnValAspAsnIleGly     145150155160     ValArgThrTyrArgSerGlnValThrMetAlaLysLysGluSerVal     165170175     TyrAspAlaAlaGlyGlnHisThrPheLeuValProValAspGluGly     180185190     PheLysLeuSerAlaArgSerSer     195200     __________________________________________________________________________ 

What is claimed is:
 1. A recombinant nucleic acid comprising a nucleotide sequence encoding the protein TC1 as described in SEQ ID NO:4.
 2. The recombinant nucleic acid of claim 1, comprising the sequence provided in FIG. 4 and SEQ ID NO:3.
 3. A nucleic acid fragment of the recombinant nucleic acid of claim 1, said nucleic acid fragment being 30 nucleotides or greater in length.
 4. A nucleic acid fragment of the recombinant nucleic acid of claim 1, said nucleic acid fragment being 40 nucleotides or greater in length.
 5. A nucleic acid fragment of the recombinant nucleic acid of claim 1, said nucleic acid fragment being 50 nucleotides or greater in length.
 6. A nucleic acid fragment of the recombinant nucleic acid of claim 1, said nucleic acid fragment having the nucleotide sequence of SEQ ID NO:1. 